The present invention relates generally to the field of hashing, and more particularly to the field of visual hashing as a security measure.
Generally, hashing transforms a string of characters into a shorter fixed-length value or key that represents the original string. Hashing is used to index and retrieve items in a database faster than methods using original values by finding the item using the shorter hashed key than to find the item using the original value. Visual hashing uses an image, such as a segment of text, a photograph, or any other visual medium, to assign a hash value to quickly identify characteristics, such as user permissions and image content classifications, associated with the image.
Hashing is also used in many encryption algorithms. By assigning hash keys to a particular segment of text or an image, a program may identify permissions associated with the hash key by processing the one or more hash keys through one or more encryption algorithms. In the case of visual hashing, the hash key is determined by key characteristics of an image such as the composition which may include, among many other characteristics, the colors and the placement of light and dark areas. Using the assigned hash key associated with a particular image, the one or more hash keys can be inserted into and encryption algorithm to produce a particular result, such as determining whether a user attempting to access information hidden in the image has access authorization.